Herbal Extracts – Possibility of Preventing Food-Borne Infection

Despite the high degree of awareness of food preservation methods, there is increasing occurrence of disease outbreaks caused by pathogenic and spoilage microorganisms in foods. Due to consumer awareness and negative perception of artificial preservatives in food, in recent years attention is shifting toward alternatives that the consumers recognize as natural. Thus, herbal extracts are now getting more space in food industry to prevent the propagation of bacteria that affect the spoilage of food or for the spread of so-called food-borne diseases. Herbal extracts, particularly essential oils (EOs), have complex composition that quality and composition depend on the method of extraction. There are now numerous reports of the in vitro antimicrobial activity of EOs in the scientific and medical literature: EOs are found to have broad-spectrum inhibitory activities against various food-borne Gram-positive and Gram-negative pathogenic bacteria. In this chapter, definition, history, and economic importance of aromatic herbs and herbal extracts, particularly EOs, are described. Also, attention has been paid to techniques for extraction, as well as chemical composition and antimicrobial activity of herbal extracts. This chapter demonstrates the possibility of usage of herbal extracts in preventing food-borne infection through literature survey and original results

The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys

To identify the most important parameters of multiscale microstructural features influencing the fracture modes and resistance to damage, detailed microstructural and fractographic analysis of overaged 7000 alloy plates are performed using the broken plane-strain fracture toughness, K-Ic, test specimens. The geometric characteristics of differently sized second-phase particles are changed by the compositional variations. It was found that the fracture process involves three main micromechanisms. The dominant fracture mode changes with alloy purity, leading to fracture toughness degradation. Quantitative description of fractures by profilometry confirmed that crack initiation and propagation is fostered by the coarse Fe- and Si-rich particles. (C) 2009 Elsevier B. V. All rights reservedMesomechanics 2009 Conference, Jun 24-26, 2009, Oxford, Englan

Chemical Composition and in Vitro Evaluation of the Antioxidant and Antimicrobial Activities of Eucalyptus gillii Essential Oil and Extracts

In this study, essential oil and various extracts (hexane, petroleum ether, acetone, ethanol, methanol and water) of Eucalyptus gilii were screened for their chemical composition, antimicrobial and antioxidant activities. The essential oil chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID), respectively. Thirty four compounds were identified, corresponding to 99.5% of the total essential oil. Tannins [104.9-251.3 g catechin equivalent (CE)/Kg dry mass], flavonoids [3.3-34.3 g quercetin equivalent (QE)/Kg dry mass], phenolics [4.7-216.6 g gallic acid equivalent (GAE)/Kg dry mass] and anthocyannins [1.2-45.3 mg cyanidin-3-glucoside equivalent (C3GE)/Kg dry mass] of various extracts were investigated. Free radical scavenging capacity of all samples was determinedt. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the IC50 of essential oil was 163.5 ± 10.7 mg/L and in the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS) assay, it was 94.7 ± 7.1 mg/L. Among the various extracts, the water extract showed the best result (IC50 = 11.4 ± 0.6 mg/L) in the DPPH assay which was comparable to vitamin C (IC50 = 4.4 ± 0.2 mg/L). The antimicrobial activities were evaluated against different bacterial and fungal strains. Gram positive bacteria were found to be more sensitive to the essential oil and extracts than Gram negative ones. Anthocyanins seem to have a major effect on the growth of Bacillus subtilis (R2 = 0.79). A significant antifungal activity was observed against the yeast and fungi. Correlations between chemical composition and antioxidant activities were studied and R2 values were about 0.96 for the effect of phenolics on the DPPH assay

A novel reformulation of the Theory of Critical Distances to design notched metals against dynamic loading

In the present study the linear-elastic Theory of Critical Distances (TCD) is reformulated to make it suitable for predicting the strength of notched metallic materials subjected to dynamic loading. The accuracy and reliability of the proposed reformulation of the TCD was checked against a number of experimental results generated by testing, under different loading/strain rates, notched cylindrical samples of aluminium alloy 6063-T5, titanium alloy Ti–6Al–4V, aluminium alloy AlMg6, and an AlMn alloy. To further validate the proposed design method also different data sets taken from the literature were considered. Such an extensive validation exercise allowed us to prove that the proposed reformulation of the TCD is successful in predicting the dynamic strength of notched metallic materials, this approach proving to be capable of estimates falling within an error interval of ±20%. Such a high level of accuracy is certainly remarkable, especially in light of the fact that it was reached without the need for explicitly modelling the stress vs. strain dynamic behaviour of the investigated ductile metals

Schutz und Erschließung von Fort Kosmač in Brajići, Montenegro

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersFort Kosmač was constructed by Austrian Empire in 1858, as fortification to protect the southern border of the empire. Abandoned and demolished by the imperial army of Austro-Hungary, in 1918 it became a part of Kingdom of Yugoslavia. It remained a ruin until today. The condition of the fort worsened over the time as it was not in any use any more. Today, it is a monument but because its bad condition, lack of infrastructure and poor approach, it is only sometimes visited by locals and hikers, who come to enjoy the great view over the Bay of Budva. The building is a ruin, completely unsecured and as such, it poses danger to the curious visitors, who want to explore the ruin. The fort lies near the main road that connects Budva with Cetinje. From the main road the old street leads to the fort, although in a bad condition, the fort is still accessible even by car over the new part recently built. The serpentine approach is partially collapsed with a danger of bigger parts collapsing the site is in danger to lose its important parts. Although protected as a national cultural monument, until now nothing has been done to physically protect it and equip it with any infrastructure for safe touristic visits.The project focuses on analyzing the site. Besides the detailed research, it should extract the best possible solutions for future treatment, to avoid the complete loss of this unique piece of history. The detailed building archaeology including a documentation of its current status will be the first part of the project. After collecting and processing the data, an analysis and evaluation will be made of what would be needed minimum to rehabilitate the site. Afterwards further options will be designed.Fort Kosmač wurde in dem Jahr 1858 von der österreichische Monarchie als Festung zum Schutz der Südgrenze des Imperiums erbaut. Von der kaiserlichen Armee Österreich-Ungarns aufgegeben und gesprengt, wurde es 1918 Teil des Königreichs Jugoslawien. Es blieb bis heute eine Ruine. Da sie nicht genutzt wurde, verschlechterte sich der Zustand der Werk im Laufe der Zeit. Heute ist es ein Denkmal, aber aufgrund seines schlechten Zustands, der fehlenden Infrastruktur und des schlechten Zugangs wird es nur gelegentlich von Einheimischen und Touristen besucht, die die herrliche Aussicht auf die Bucht von Budva genießen. Das Gebäude ist eine Ruine und völlig ungesichert, und als solches stellt es eine Gefahr für neugierige Besucher dar, die die Ruine auf der Suche nach einer besseren Sicht erkunden möchten. Das Bauwerk liegt in der Nähe der Hauptstraße, die Budva mit Cetinje verbindet. Von der Hauptstraße führt die alte Straße zur Festung, die kurz vor dem Werk erbaut wurde. Derzeit ist die Straße in einem schlechten Zustand, aber das Bauwerk ist trotzdem über den neugebauten Teil der Straße mit dem Auto erreichbar. Die Gebäudeteile sind teilweise eingestürzt, wobei die Gefahr besteht, dass weitere, größere Teile einstürzen und mit ihnen der wichtigste Teil des Festungsbereichs und der Standort verloren gehen. Obwohl als nationales Kulturdenkmal ünter Schutz gestellt, wurde bis jetzt nichts unternommen, um es physisch zu schützen und mit der Infrastruktur für sichere Touristenbesuche auszustatten. Das Projekt konzentriert sich darauf, das Bauwerk mit seinem Standort zu analysieren und durch detaillierte Recherchen die bestmöglichen Lösungen zu finden, wie es in Zukunft behandelt werden sollte, um den vollständigen Verlust des einzartigen Bauwerks zu vermeiden. Die detaillierte Untersuchung des Gebäudes und seiner Geschichte bildet den ersten Teil des Projekts, das durch eine Dokumentation des aktuellen Zustands unterstützt wird. Nach der Erhebung und Analyse der Informationen wird festgesetzt, welche Mindestanforderungen nötig sind und welche realistischen weiteren Möglichkeiten es für diesen Ort gibt.32

Micromechanical modelling of fracture toughness in overaged 7000 alloy forgings

In this article, a multiple micromechanisms-based model that quantitatively relates the plane-strain fracture toughness, KIC, of overaged 7000 alloy forgings to their microstructural attributes, fracture surface morphology and basic tensile properties is developed. To verify the proposed model, extensive microstructural and fractographic analyses along with mechanical tests are carried out using three industrially produced alloys with different contents of Fe and Si impurities. The fracture mechanisms are identified and individual contributions to the overall fracture are quantitatively assessed. The fracture toughness is then calculated using the experimentally obtained average values of relevant mechanical properties, area fractions of main fracture modes and microstructural parameters such as volume fraction of coarse intermetallic (IM) particles, their size and spacing, density of intragranular precipitates, number and width of the precipitate-free zones (PFZ). The proposed model correctly predicts the effect of individual microstructural parameters on the overall fracture behaviour

The effect of compositional variations on the fracture toughness of 7000 al-alloys

To provide an understanding of how compositional variations affect the microstructural parameters associated with coarse intermetallic (IM) particles and the fracture toughness in AA 7000 aluminum forgings, a microstructural and fractographic analysis as well as mechanical tests were carried out on three industrially produced Al-Zn-Mg-Cu alloys with different contents of impurities (Fe+Si). Light optical microscopy and image analysis were used to assess the volume fraction, size and distribution of all the soluble and insoluble coarse ( gt 0.1 mu m) IM particles identified in the corresponding R-C and L-R planes for T73-type heat treatments by selective etching and energy-dispersive X-ray spectroscopy. These quantitative data were correlated with the plain-strain fracture toughness, K-IC, with the results being, used to produce useful information on alloy design and thermomechanical processing via microstructural control. The scanning electron microscope observation of fracture surface features and an estimation of the area fractions of different fracture modes in the plastic zone segments of a test specimen showed that multiple failure mechanisms occurred with coarse voiding at the intermetallics becoming more important as the fraction of coarse IM particles increases. A quantitative assessment of the relevant microstructural and fractographic parameters will be utilized for developing and verifying a multiple micromechanisms-based model for fracture toughness

Fractographic analysis of fatigue damage in 7000 aluminium alloys

In this paper, an attempt is made to correlate the fatigue damage in 7000 aluminium alloys with different impurity contents to the microstructural features and to explain their interdependence through fractographic observations. The Paris constants of these alloys in the form of hot-forged plates subjected to the overaged T73 temper are evaluated and differences in the fatigue crack growth rate described by striation spacing measurements. Scanning electron microscopy analysis of fatigue fracture surfaces revealed that the type and morphological parameters of coarse intermetallic particles play a critical role in fatigue crack growth behaviour. The elemental distribution determined by means of energy-dispersive spectroscopy analysis showed that the fractured particles accelerating the crack advances are larger particles of Fe-rich phases. The fatigue crack growth rate increases considerably with increasing amounts of these particles. The smaller η, S and Mg2Si particles contribute beneficially to fatigue life